BAGHDAD - Iraq's dwindling Christian community was grieving and afraid on Monday after militants seized a Baghdad church during evening Mass, held the congregation hostage and triggered a raid by Iraqi security forces. The attack left at least 52 people killed and 67 wounded — nearly everyone inside.

The attack, claimed by an al-Qaida-linked organization, is the latest assault against Iraq's Christians, whose numbers have plummeted since the 2003 U.S.-led invasion as the community has fled to other countries.

Outside Our Lady of Deliverance church, Raed Hadi leaned against the car carrying his cousin's coffin, waiting for the police to let him bury him on church grounds.

"It was a massacre in there and now they are cleaning it up," he said Monday morning. "We Christians don't have enough protection ... What shall I do now? Leave and ask for asylum?"

"Now they make a show," said Jamal Jaju, who watched as Iraqi forces set up a chain link fence around the church and pushed back observers. "What can I say? I lost at least 20 friends in there."

Pope Benedict XVI denounced the assault as "ferocious" and called for renewed international efforts to broker peace in the region. Catholics made up 2.89 per cent of Iraq's population in 1980; by 2008 they were merely 0.89 per cent.

Islamic militants have systematically attacked Christians in Iraq since the collapse of Saddam Hussein's regime.

Sunday's bloodbath began at dusk, when militants wearing suicide vests and armed with grenades attacked the Iraqi stock exchange. Only two guards were injured in the assault, which may have been an attempt by the militants to divert attention from their real target — the nearby church in an upscale Baghdad neighbourhood.

That attack soon followed. The gunmen went inside the church and took about 120 Christians hostage.

Maj. Gen. Hussein Ali Kamal, the deputy interior minister, said 52 people were killed and 67 wounded. The dead included at least 10 policemen, two priests and five to eight attackers, according to various accounts.

It was unclear whether most hostages died at the hands of the attackers or during the rescue.

According to two security officials, most of the deaths were in the basement where a gunman killed about 30 hostages when Iraqi forces began to storm the building. One official said the gunman set off an explosives vest he was wearing, but the other said the gunman threw two grenades at his hostages. Both spoke on condition of anonymity because they were not authorized to talk to journalists.

Video footage from an American drone that was overhead during the attack showed a black plume of smoke pouring out of the church followed by flashes before security forces charged inside. U.S. forces often supply air support to Iraqi forces conducting operations on the ground, feeding them video footage from their airborne drones.

"We have no clear picture yet whether the worshippers were killed by the security forces' bullets or by terrorists, but what we know is that most of them were killed when the security forces started to storm the church," said Christian lawmaker Younadem Kana, who condemned the operation as "hasty" and "not professional."

Baghdad military spokesman Maj. Gen. Qassim al-Moussawi said Monday that security forces arrested five suspects, some of whom were not Iraqi.

A cryptically worded statement posted late Sunday on a militant website allegedly by the Islamic State of Iraq appeared to claim responsibility for the attack.

The group, which is linked to al-Qaida in Iraq, said it would "exterminate Iraqi Christians" if Muslim women in Egypt were not freed.

It specifically mentioned two women that extremists maintain have converted to Islam and are being held against their will in Egypt.

The two are wives of priests. Some believe they converted to Islam to leave their husbands since divorce is banned by Egypt's Coptic Church. One woman disappeared in 2004 and the other this past July.

Egypt's Christians had originally maintained they were kidnapped and staged rallies for their release. In both cases, police subsequently recovered the two women, who denied they had converted. They were then spirited away to distant monasteries.

The cases were widely publicized in Egypt, which has its own fraught sectarian relations, have continued to be a rallying point for Egypt's hardline Muslims. They hold weekly demonstrations in mosques calling for the women's "release."

Bishop Morqos, an assistant to Egypt's Coptic pope, told The Associated Press that the women fear for their lives and will remain in seclusion.

"The two are afraid to appear in public, fearing assassination by extremists," he said.

In their message Sunday, the militants called on the Vatican, which held a meeting last month to discuss the fate of Christians in the Middle East, to release the women.

"We direct our speech to the Vatican and say that as you met with Christians of the Mideast a few days ago to support them and back them, now you have to pressure them to release our sisters, otherwise death will reach you all," it said.

On Monday, Iraqi authorities took extra measures to protect Christian neighbourhoods and churches in Mosul, Kirkuk and Baghdad. Additional police cars and checkpoints were seen near many churches, and authorities were conducting extensive searches on cars and pedestrians heading to churches.

"This is more than a tragedy," said Iraq's Human Rights minister, Wijdan Mikheil, who is a Christian.

Choking back tears as she spoke with reporters outside Our Lady of Deliverance church, she said: "What is happening to Iraqis in general and Christians in particular is an attempt to push them out of the country, but we hope Iraqis remain united."

Our Lady of Deliverance is a Syrian Catholic church
Karim Khalil, a 49-year-old Iraqi Christian, said he moved to Syria with his family last year because he felt his religion made him a target in Baghdad.

"Iraqi militias threatened me, saying I was on the side of the Americans because I am Christian," Karim told the AP. "They said I would be killed if I stayed in Iraq."

Now he lives in Damascus with his wife and five children.

"I have left behind my house and everything to escape with my family," he said.

Many other Iraqi Christians living in Syria refused to speak to the AP. They said they fear militias may exact revenge on their families in Iraq.